1. Field of the Invention
The present invention relates to a control device for controlling selection of gear ratio in secondary transmission provided in a vehicle which is used in addition to an ordinary main transmission.
2. Description of the Prior Art
The secondary transmission is connected to the main transmission in series to change the gear ratio thereof and it has widely been used in such a vehicle as an automobile for improving a fuel consumption ratio in high-speed and middle-speed running situations of the vehicle and decreasing engine noises of the vehicle.
In a conventional device selecting the gear ratio in such a secondary transmission, however, the selection of the gear ratio in the secondary transmission can be conducted without depressing a clutch pedal. Accordingly, there is a problem that the gears in the secondary transmission are sometimes over-loaded due to misoperations by a driver in the vehicle.